Use of DWI-only MR protocol for screening stroke mimics.

PURPOSE: Patients presenting with focal neurological symptoms may suffer from stroke or stroke mimics. Diffusion weighted MRI (DWI) is highly sensitive for identifying acute ischemia. Therefore, we aimed to explore whether a DWI-only protocol would help differentiate stroke from stroke mimics.

METHODS: We identified all patients with possible but not definite stroke that underwent DWI-only MRI between 6/2010 and 8/2011. Patients with a positive DWI lesion were compared to those with negative DWI findings on demographics, risk factor profile, final discharge diagnoses, and outcome.

RESULTS: A total of 124 patients were included with a median age of 63.5 (53% male). DWI MRI was positive for acute ischemia in 46 patients (37%). The most frequent stroke mimics were peripheral vertigo (n=19), acute confusion (n=10), seizures (n=9) and migraine with aura (n=8). Most ischemic lesions were small on DWI (<2 cm) and patients had minor disability (mean NIHSS 4.9±3.9) with 81% of patients having good outcomes (modified Rankin Score≤2) at 3 months. On univariate analysis patients with positive DWI studies had higher frequencies of having more than one clinical symptom (56% vs. 13% respectively; P<0.001) and this variable remained a significant predictor for stroke on multivariate analysis (OR 9.4 95% CI 3.8-23.5).

CONCLUSIONS: A short DWI-only MRI protocol can effectively differentiate stroke from stroke mimics and could be used in settings of the emergency department as well as later on for diagnostic purposes. The chances for finding positive DWI lesions are increased in patients with multiple symptoms and signs.